Roller rail for industrial heat treating furnaces



' Sept. 12, 1939.

H. HARRIS 2,172,381

ROLLER RAIL FOR INDUSTRIAL HEAT TREATING FURNACES FiledMarch 19, 1938 22 22 2526 2012 22 Ti .l. 3 12 12 22 32 \III/ 7 INVENTOR ATTO R N EYS UNITED STATES PATENT OFFICE ROLLER RAIL FOR INDUSTRIAL HEAT TREATING FURNACES Henry H. Harris, Champaign, Ill.

Application March 19,

7 Claims.

My invention relates to industrial heat treating furnaces, such as carburizing furnaces, and the like, and specifically is concerned with the means employed within the furnace on which to move articles therethrough.

Articles to be heat treated within furnaces of this type are usually loaded onto flat bottomed supports, such as trays, boxes, or the like. These supports are disposed on top of, and overlie skid rails, tracks or on various types of roller rails, usually two or three of which are disposed within and extend lengthwise of the furnace. The supports are then usually pushed or otherwise moved through the heat treating furnace in tandem. The flat skid rails have been found to be unsatisfactory, both because of the destructive effects of the friction generated by the flat-bottomed supports, and because of the injurious effects of the heat conditions within the furnace which, with the load-bearing stresses, cause warping, buckling and bending of the rails.

Ordinarily, roller rails, that is, rails on which rollers are mounted, while not subject to the destructive effects of travelling friction to the same extent as are flat skid rails, are nevertheless subject to the injurious effects of furnace heat and work support and travel thereon. Even when made heavy and bulky, as they usually are, they warp and buckle, and the roller components thereof shift-out of line and are not all contacted by the work supports passing thereover.

It is the main object of my invention to provide a roller rail in which the possibility of shifting and failure to bear properly will be reduced.

A further object of my invention is the provision of a roller rail which is made up of a plurality of units linked or otherwise secured together.

A further object of my invention is the provision of a roller rail which is made up of a plurality of linked-together units movable relatively to each other during work travel thereover.

A further object of my invention is the provision of a roller rail in which the roller bearings are so related to the load or work passing thereover, as to distribute the load therebetween.

A further object of my invention is the provision of a roller rail on which the rollers are so disposed as to be brought successively into bearing contact with the load passing thereover.

Another object of my invention is the provision of a roller rail so constructed that a roller, on first being engaged by the load, will bow thereunder so as not to interfere with the load travel,

1938, Serial No. 196,851

and later will raise up to serve as a support at a higher level.

Other and related objects of my invention will in part be apparent, and in part be obvious from the following description of several illustrative embodiments thereof.

In the drawing annexed hereto and made a part hereof:

Figure l is a plan view of one form of device constructed according to and embodying my said 10 invention, with parts broken away to show the interior construction;

Fig. 2 is a side elevational view thereof, also with parts broken away;

Fig. 3 is a transverse section along the broken line 3-3 of Fig. 2; and

Fig. 4 is an end view showing a modified arrangement for mounting a rail of my invention within a furnace.

Reference numeral It! indicates generally the form of roller rail illustrated in Figs. 1, 2 and 3, which comprises a number of roller supports I2 secured together by links M to form a roller rail unit.

Each roller support I 2 comprises a hollow rocker shoe member I8, the underside ll of which is curved so that the shoe can rock back and forth. The rocker shoe member I6 is hollow, the interior chamber I8 being open at the top to provide a longitudinal slot 20, and the shoe I5 is closed at the bottom. Pairs of transversely aligned notches 22 are formed in the upper edges of the side walls 24 of rocker shoes it, which notches 22 form bearings for the pintles 25 of rollers 26. Pintles 25 are preferably formed as 5 an integral part of the rollers 26. In the form shown in Fig. 2, I provide two pairs of transversely aligned notches 22, 22, one near each end thereof, equidistantly from the center, so that the roller shoe will be level while no load is passing thereover.

The open longitudinal slot 20 is preferably narrower than the interior chamber, and the upper parts 28 of the sidewalls i8 are shouldered inwardly as indicated at 30 and thereby made thicker than the lower portions 32 of the sidewalls. Thus the bearing slots or notches 22 for receiving roller pintles 25 are lengthened to afford more wearing surface and longer life. Notches 22 are of greater depth than the diameter of pintles 5O 25 so that when the rollers 22 are placed with their pintles 25 within the slots, the rollers will be prevented from jumping out of their bearings upon rocking motion of the shoe members.

Rocker shoes l6 and rollers 26 are'each formed preferably as one piece castings of a heat and corrosion resisting metal alloy, as nickel, chromium and iron composition.

A plurality of rocker shoes l6, l6 are disposed in end-to-end relationship, and secured in such relationship by means of link members I4 to form a rail.

Link members are preferably arranged in pairs, one on each side of the shoes. One end of link [4 is pivotally secured to the side wall of one rocker shoe I6 by a pivot pin or bolt 36. The opposite end of link 34 is slidably secured to the adjacent rocker shoe, as by means of a pivot pin or bolt 33 coacting with a longitudinal slot in said link.

The line of rocker shoes equipped with upwardly projecting rollers forms a furnace track. To keep the shoes in line they may be disposed and received in an open longitudinal groove in the furnace floor or in a channel bar or the like, a separate channel bar 4| being shown in Fig. 3 for this purpose.

In use, a number, as two or three, of the roller rails constructed as described are arranged parallel to one another, so that the work is supported at intervals across the width of the furnace.

Another modification of my invention is shown in Fig. 4. Instead of having a flat bottomed shoe, as shown at 42 in Fig. 3, the curved rocker part of the shoe is provided with depending flanges 44, one at each side thereof. For this form of rocker, a support may be provided in the form of a fiat bar 46, as shown in Fig. 4, and of such width that the depending flanges 44 straddle the sides of the bar.

The tray or other work support is preferably of such dimension in the direction of travel as to cover or overlie two or more of the shoes l6. As the work support is moved through the furnace it bears upon the rollers of any one shoe member after another, and the rocking action of the shoes upon their rocker bottoms serves to bring about efficient rolling support for the trays or other work support upon the several rollers of the rocker shoes even though there may be considerable variation in roller diameter, depth of bearing slots, and the like.

As the work travels from shoe to shoe the nearest roller of each shoe at first contact is easily depressed by reason of the rocking action of the shoe, and as the work travel proceeds, the roller rises up afterward and bears against the underside of the work support and takes its weight. In this way the work can progress smoothly and without hindrance with proper roller support as it is put through the furnace.

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. In a roller rail, a plurality of rocker roller bearing members disposed in end-to-end relationship, and means to secure said members in said relationship comprising links.

2. In a roller rail, a plurality of rocker shoe roller bearing members disposed in end-to-end relationship, and means to secure said members in said relationship, said securing means allowing said members to rock relative to each other.

3. A roller rail comprising a plurality of rocker shoe members disposed and secured in end-to-end relationship, transversely aligned bearing slots in the sidewalls of said rocker members, and rollers mounted for rotation therein, said rollers being disposed adjacent each end of the rocker member, equidistantly from the center thereof.

4. In a load-supporting roller rail, a rocker shoe member, a plurality of rollers mounted for rotation therein, rocking action of said shoe serving to distribute the load equally between the rollers.

5. In a load-supporting roller rail, a rocker shoe member, a plurality of rollers mounted for rotation in said shoe, rocking action of the shoe bringing each successive roller to bear on the underside of the load during load travel over the rail.

6. In a heat treating furnace, a roller rail, means to mount said rail within the furnace, said roller rail comprising a plurality of fiat-bottomed rocker roller-bearing members, and said mounting means comprising a channel member adapted to receive the rail therewithin and permit the roller-bearing members to rock relative to each other.

'7. In a heat treating furnace, a roller rail, means to mount same within the furnace, said roller rail comprising a plurality of flat-bottomed rocker roller-bearing members, flanges depending from the sides of said bearing members, and said mounting means comprising a fiat-topped rail member adapted to receive the roller rail thereon and permit the roller-bearing members to rock relative to each other, the depending flanges straddling the sides of the fiat-topped rail member.

HENRY H. HARRIS. 

